System for sorting documents



United States Patent 3,343,672 SYSTEM FOR SORTING DOCUMENTS Hans Jacobus de Vries, Leidschendam, and Arie Adriaan Spanjersbcrg, Leiderdorp, Netherlands, assignors to De Staat der Nederlanden, ten Deze Vertegenwoordigd Door de Directeur-Generaal der Posterijen Telegrafie en Tclefonie, The Hague, Netherlands Filed June 17, 1965, Ser. No. 464,685 Claims priority, application Netherlands, June 26, 1964, 647,349 8 Claims. (Cl. 209-74) ABSTRACT OF THE DISCLOSURE An electronic shift register controlled device for controlling the sorting of documents as they pass through isochrone (equal time) sections of branching channels from the document input of the device. The improvement resides in photoelectric sensing means between each isochrone section coupled with the electronic shift register for detecting errors in the shorting of the documents at the locations which the errors occur.

Related applications Netherlands priority application Ser. No. 6,407,349, filed June 26, 1964.

Summary of invention The invention relates to a system for sorting documents, such as letters, which documents are provided with a sorting code in which the discharge points of the letters are chosen by combinations fixed at a central point or station for controlling a number of clack gates or switches in the system.

According to the invention the transport of documents or letters is divided into one main channel and a branch of channel sections, each section and each discharge point or output lying between isochrones, which isochrones are lines between points with equal letter propogation times from a common document input station. Central registers are provided foreach channel isochrone section in which the information stored is in accordance with the vertical channel and the discharge gate in that channel which is to be chosen for that document or letter. Since the outputs along the channels are grouped according to isochrones, only one document or letter can be in one channel isochrone section at a time.

In a particular case the dividing system is built up with a horizontal supply-channel with switches into a number of vertical channels, each of which vertical channels has switches and casting-oif points for the letters.

The beginning of each isochrone channel section is marked with a photo-electric cell. If the front of a document or letter reaches the beginning of such a section, a photoelectric cell which marks that section, delivers an impulse, Which'is used to shift the information from the registers belonging to the previous isochrone channel section to the registers of the isochrone channel section in which the front ofthe document or letter appears.

In a system of this kind jams can occur by jamming of the document or letter. Moreover it is possible that through a disturbance, a switch does not follow the electrical control commands in which case missorting will occur.

With the aid of the impulses of the photoelectric cells which mark the channel sections and of the information in the registers, jams and missortings can be detected. By means of a lamp monitor, adapted for this purpose, the place where a jam or a missorting has occurred, is automatically signalled.

A dividing system with in vertical channels and n 'ice casting-off points per vertical channel operates with a p bit code, generally requiring a shift register with a total capacity of 2 m p-i-mnp bits. If the vertical channels are adjusted in such a way that the casting-oh" points are on equal height opposite to each other, the necessary register capacity amounts to 2 mp+ /2 mnp bits. Due to the division into isochrones channel sections, the required register capacity becomes smaller, viz mp+(m+n)p resp.

bits.

Brief description 0 views The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be understood best by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram showing an isochrone dividing system according to one embodiment of this invention with a horizontal channel and a number of descending channels, and with a reading station for the scanning of the marks on the document or letter which reading station is followed by a number of shift registers for the control of the switches in said channels;

FIG. 2 shows an enlarged schematic side view of two switches or clack gates in a vertical channel for two casting-oti points lying at the same or equal height;

FIG. 3 shows a table for the binary metering of the registers with a decimal translation;

FIG. 4 shows a diagram of the signalling lamps for the signalling of jams for a system as shown in FIG 1; and

FIG. 5 is a schematic block wiring diagram of a part of the control and check circuits for the system of FIG. 1.

Detailed description FIG. 1 shows a horizontal channel h with a number of descending channels g1 through g8 leading to the outputs, discharge points, or stores. The letters or documents are led one at a time into the channel h after being taken from the stack a by means of a feeding device b and then being led further past the reading device 1. The destination of the letter is indicated on it in code signals and the code signals are scanned With the aid of the reading device 1 and converted into electrical impulses which are stored in two sets of three triggers in the controller circuit S.

\Vith the aid of the controller circuit S the information is checked for validity and temporarily stored in a binary code in its triggers before being shifted through triggers Sla through 812a and Slb through S7b as the document or letter passes one of the diagonally connected isochrone photocells until the correct combination of pulses from the register triggers operates the thus selected switch or clack gate via a circuit similar tothat shown in FIG. 5

described later.

channel.

When the front of the letter has passed the photo-electric cell f1 the letter is in the first diagonal isochrone channel section. Thus terminals of this isochrone channel sec tion are marked by the photo-electric cells 2 and 11.1; the terminals of the second isochrone channel section are marked by the photo-electric cells f3, 12.1 and f1.2., etc.

The information transport by the shift register can now take place in such a way that, if e.g. one of the photoelectric cells f3, f2.1 or f1.2 is obscured, the information contents of the shift registers 82a and 521) are transported or shifted to the next registers re'sp. 53a and 53b. For the remaining isochrone channel sections this occurs in the same way. The switches or clack gates in an isochrone channel section are connected via a logical circuit with the shift register sections for that isochrone channel section. If e.g. the information contents of shift register section Slb is 001 (thus a binarily coded l) the clack gate or switch k1 will be energized and the letter or document is conveyed into the vertical channel g1. If the letter is further destined for the second store in that channel g1, the binary information will, at the instant that the photocell f1.1 is covered by the front of the letter, be forwarded into shift register section 52a, which causes the excitation of clack gate or switch k1.2v

The sorting process for the remaining destinations takes place in an identical way. A number of documents or letters can be in the outlet channels simultaneously; however, one letter can only be present per diagonal isochrone channel section shown in FIG. 1.

The lower ends of the vertical channels g1 through g8 are connected with the return channel r. If a document or letter does not find a switch, clack gate, or discharge point on its way in the sorting system so that that letter is brought into a store, this document or letter is transported to the return channel r.

In FIGURE 2 two switches or clack gates lying at the same or an equal height in a vertical channel are indicated. These can be e.g. the clack switches or clack gates k1.1 and k1.2 of the first vertical channel g1 in FIG. 1. These clack gates k1.1 and k1.2 are drawn in full lines in their unoperated positions, wherein the electromagnets which work them, are not energized. In such a case a document or letter will pass both clack gates and be conveyed further downwards through the vertical channel g1.

FIG. 5 shows the part of the control and checking circircuit which relates to the third isochrone channel section in FIG. 1. If the front of a letter passes one of the photocells f3, 12.1 or 71.2, one of the inputs of the OR-gate P1 becomes negative. The output of the converting amplifier or inverter V1 then becomes positive which combination forms a NOR-gate G10. By means of the AND-gates P2 through P7, working with the positive polarity, the information from the shift register sections 52a and 52b is transferred into the sections S312 and S312 (the latter two groups of triggers 82b and 53b are not shown in FIG. 5 to reduce its complexity).

It is supposed that a document or letter is destined for the second store in the vertical channel g2.

At the moment when the output of the converting amplifier or inverter V1 obtains the positive polarity, the binary information 010 appears at the outputs of the registers 83a (and registers 83b also connected to AND- gates P8 and P9 as are the registers shown), which causes in the AND-gate P9, working at the negative polarity, a negative polarity at its output.

Via the converting amplifier or inverter V3 the electromagnet of the clack gate k2.2 is energized, which causes the letter during the transport through the channel g2 to be delivered to the desired first store. If at the output of the registers 83a the information 001 is present, the electromagnet of the other clack gate k2.1 at the same level or height is energized via an identical circuit, and letter then delivered in the other or second store at that level.

If one of the electromagnets of the clack gates k2.1 or k2.2 is energized, the OR-gate P10 has a negative output potential. If the photo-electric cell 12.1 is covered by the front of the letter, a negative potential impulse will appear at the output of the impulse-shaping network D1 with a little longer duration of time than needed for a letter to pass through that isochrone channel section.

1f in the above-mentioned example the clack gate k2.2

is not in the correct position, the letter will not be delivered in the store but after a certain time, the following photo-electric cell 12.2 in the next isochrone channel section will be covered, by which a negative potential appears at the output of that photoelectric cell. In that case a negative potential will appear at the output of the AND-gate P11, working at the negative polarity, which potential reaches the OR-gate P12 and the converting amplifier or inverter V4, or the NOR-gate G12. In the output circuit of inverter V4, a jam lamp L2.1 may be inserted, which will be lighted in the described case to signal that the clack gate k2.2 did not operate. The place of the lamp on the monitoring table, which is shown in FIGURE 4, indicates where the fault appears. Also connected to the circuit from the NOR-gate G12 may be an emergency switch to stop the whole device.

In the case that a letter must not be delivered in the stores 1 or 2 of the vertical channel g2, the OR-gate P10 will carry a positive potential at its output. Consequently, a negative potential is at the output of the converting amplifier or inverter V 5. At the output of the impulse-shaping network D2 a negative impulse of short duration will appear at the terminal of the impulse, which impulse is delivered by the impulse-shaping network D1. During the presence of the impulse from network D2, the letter must have reached the following isochrone channel section; consequently, the output of the converting amplifier V6 or NOR-gate G13 must carry the positive polarity and the jam lamp L2.1 or alarm is not operated. However, if there is a jam, this is not the case and then the output of the AND-gate P13 working at the negative polarity becomes negative, by which the signalling lamp L2.1 is also lighted again via the NOR-gate G12.

Similar circuits are employed for the remaining signalling lamps.

While we have illustrated and described what we regard to be the preferred embodiment of our invention, nevertheless it will be understood that such is merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

We claim:

1. A device for sorting documents into a plurality of outlets, said device comprising:

(a) means (b) for feeding the documents one at a time into and through said device,

(b) means (S) for setting up bits of information in a set of triggers corresponding to said outlets,

(c) means (f) for detecting the leading edge of each document fed through said device at substantially equal time-distance intervals throughout said device,

(d) a main (h) and a plurality of branch (g1 through g8) channels from said feeding means for passage of said documents, along which channels said detecting means are relatively evenly distributed and located,

(e) a step register means (Sla through 512a and Slb through 8715) for said information bits set up in said triggers, which register means is stepped each time a documents leading edge passes one of said detecting means in said channels,

(f) switch means (k1 through k8) for said documents between said main and each said branch channels, and switch means (k1.1 through k8.8) in said branch channels between each said detecting means for discharging said documents into said outlets,

(g) separate electronic gate means (P8, P9) corresponding to each said switch means and each said information bits, whereby each document is switched into its corresponding outlet when it reaches its said branch channel and its said outlet at its passage through said device, and

(h) timing means (D1, D2, L1 through L8, and L1.1 through L8.4) controlled by said detecting means and said gate means for detecting irregularities in the movements of said documents through said device.

2. A device according to claim 1 wherein said detecting means comprises photoelectric cell means.

3. A device according to claim 1 wherein said switch means include clack gates operated by electromagnetic means.

4. A device according to claim 1 including a pair of switch means between each detecting means in each said branch channel.

5. A device according to claim 1 wherein said timing means controls the operation of said gate means when a document is to be delivered at its adjacent output.

6. A device according to claim 1 wherein said timing means for detecting irregularities includes an alarm means.

7. A device according to claim 6 wherein said timing means includes means for preventing the operation of said alarm means when a document must not be delivered to an adjacent output.

References Cited UNITED STATES PATENTS 2,900,146 8/1959 Hafner.

3,068,451 12/1962 Bolander 20974 X 3,136,423 6/ 1964 Delplace 20911l.7 3,141,540 7/1964 Burkhardt 209-72 X M. HENSON WOOD, I R, Primary Examiner.

R. A. SCHACHER, Assistant Examiner. 

1. A DEVICE FOR SORTING DOCUMENTS INTO A PLURALITY OF OUTLETS, SAID DEVICE COMPRISING: (A) MEANS (B) FOR FEEDING THE DOCUMENTS ONE AT A TIME INTO AND THROUGH SAID DEVICE, (B) MEANS (S) FOR SETTING UP BITS OF INFORMATION IN A SET OF TRIGGERS CORRESPONDING TO SAID OUTLETS, (C) MEANS (F) FOR DETECTING THE LEADING EDGE OF EACH DOCUMENT FED THROUGH SAID DEVICE AT SUBSTANTIALLY EQUAL TIME-DISTANCE INTERVALS THROUGHOUT SAID DEVICE, (D) A MAIN (B) AND A PLURALITY OF BRANCH (G1 THROUGH G8) CHANNELS FROM SAID FEEDING MEANS FOR PASSAGE OF SAID DOCUMENTS, ALONG WHICH CHANNELS SAID DETECTING MEANS ARE RELATIVELY EVENLY DISTRIBUTED AND LOCATED, (E) A STEP REGISTER MEANS (S1A THROUGH S12A AND S1B THROUGH S7B) FOR SAID INFORMATION BITS SET UP IN SAID TRIGGERS, WHICH REGISTER MEANS IS STEPPED EACH TIME A DOCUMENT''S LEADING EDGE PASSES ONE OF SAID DETECTING MEANS IN SAID CHANNELS, (F) SWITCH MEANS (K1 THROUGH K8) FOR SAID DOCUMENTS BETWEEN SAID MAIN AND EACH SAID BRANCH CHANNELS, AND SWITCH MEANS (K1.1 THROUGH K8.8) IN SAID BRANCH CHANNELS BETWEEN EACH SAID DETECTING MEANS FOR DISCHARGING SAID DOCUMENTS INTO SAID OUTLETS, (G) SEPARATE ELECTRONIC GATE MEANS (P8, P9) CORRESPONDING TO EACH SAID SWITCH MEANS AND EACH SAID INFORMATION BITS, WHEREBY EACH DOCUMENT IS SWITCHED INTO ITS CORRESPONDING OUTLET WHEN IT REACHES ITS SAID BRANCH CHANNEL AND ITS SAID OUTLET AT ITS PASSAGE THROUGH SAID DEVICE, AND (H) TIMING MEANS (D1, D2, L1 THROUGH L8, AND L1.1 THROUGH L8.4) CONTROLLED BY SAID DETECTING MEANS AND SAID GATE MEANS FOR DETECTING IRREGULARITIES IN THE MOVEMENTS OF SAID DOCUMENTS THROUGH SAID DEVICE. 